div.overflow_1 {
    width: 300px;
    height: 100px;
    border: 1px solid brown;
    overflow: hidden;
  }
  div.overflow_2 {
    width: 100px;
    height: 50px;
    border: 1px dashed rebeccapurple;
    font-size: 200%;
    overflow: auto;
  }
  .box {
    width: 400px;
    height: 50px;
    border: 3px solid green;
    margin-top: 10px;
    background-color: rgb(0, 255, 170);
  }
  .pos_static {
    position: static;
  }
  .pos_relative {
    background-color: green;
    position: relative;
    left: 10px;
    top: 20px;
    z-index: -10;
  }
  .pos_fixed {
    background-color: royalblue;
    position: fixed;
    top: 0;
    right: 0;
  }
  .pos_absolute {
    background-color: brown;
    position: absolute;
    top: 100px;
    left: 200px;
  }
  .menu:hover + .pos_absolute_menu {
    display: block;
  }
  .pos_absolute_menu {
    display: none;
    background-color: pink;
    position: absolute;
    top: 46px;
    left: 0px;
  }
  .pos_sticky{
    position: sticky;
    position: -webkit-sticky;
    background-color: orange;
    bottom: 100px;
    margin-left: 500px;
  }
  .box_float {
    float: left;
    background-color:red;
    margin-left: 20px;
  }
  .bfd {
    clear: both;
  }
  li {
    float: left;
    width: 100px;
    border: 1px solid black;
  }